Skip to main content
U.S. flag

An official website of the United States government

Publications

Below is a list of WERC's peer-reviewed publications. If you are searching for a specific publication and cannot find it in this list, please contact werc_web@usgs.gov

Filter Total Items: 3617

Insular biogeographic origins and high phylogenetic distinctiveness for a recently depleted lizard fauna from Christmas Island, Australia

Striking faunal turnover across Asia and Australasia, most famously along the eastern edge of the Sunda Shelf or ‘Wallace's Line’, has been a focus of biogeographic research for over 150 years. Here, we investigate the origins of a highly threatened endemic lizard fauna (four species) on Christmas Island. Despite occurring less 350 km south of the Sunda Shelf, this fauna mostly comprises species f
Authors
Paul M. Oliver, Mozes P. K. Blom, Harold G. Cogger, Robert N. Fisher, Jonathan Q. Richmond, John C. Z. Woinarski

Ground-nesting great horned owl in Suisun Marsh, California

Great horned owls (Bubo virginianus) are widespread throughout North, Central, and parts of South America (Artuso et al. 2013). Across this range, great horned owls are generalists, occupying a diverse range of habitats including deciduous and coniferous forests, wetlands, and agricultural landscapes. Within these habitats, great horned owls are generally found near upland or short-vegetation habi
Authors
Shannon Skalos, Matthew J. Falcon, Olivia Wang, Andrea Lynn Mott, Melissa Hunt, Orlando Rocha, Josh T. Ackerman, Michael L. Casazza, Joshua M. Hull

An objective road risk assessment method for multiple species: ranking 166 reptiles and amphibians in California

ContextTransportation and wildlife agencies may consider the need for barrier structures and safe wildlife road-crossings to maintain the long-term viability of wildlife populations. In order to prioritize these efforts, it is important to identify species that are most at risk of extirpation from road-related impacts.PurposeOur goal was to identify reptiles and amphibians in California most susce
Authors
Cheryl S. Brehme, Stacie A. Hathaway, Robert N. Fisher

Fire and invasive plants

No abstract available.
Authors
Robert C. Klinger, Matthew L. Brooks, John M. Randall

Thamnophis sirtalis fitchi (Valley Gartersnake). Coloration.

During surveys for Thamnophis gigas (Giant Gartersnake), I observed an adult T. sirtalis fitchi with unusual coloration— a yellow-cream background color with some typical red coloration laterally, but with very minimal amounts of the dark slate-black (along the sides of the yellow dorsal stripe and on top of the head) that normally predominates in this subspecies (Fig. 1; LACM [Natural History Mus
Authors
Alexandria M. Fulton

Actinemys marmorata (Western Pond Turtle): Suspected predation/scavenging

No abstract available.
Authors
Mickey Agha, Brian D. Todd, Shannon Skalos, Matthew J. Falcon, Michael L. Casazza, Olivia Wang

Evaluation of social attraction measures to establish Forster’s tern (Sterna forsteri) nesting colonies for the South Bay Salt Pond Restoration Project, San Francisco Bay, California—2017 Annual Report

Forster’s terns (Sterna forsteri), historically one of the most numerous colonial-breeding waterbirds in South San Francisco Bay, California, have had recent decreases in the number of nesting colonies and overall breeding population size. The South Bay Salt Pond (SBSP) Restoration Project aims to restore 50–90 percent of former salt evaporation ponds to tidal marsh habitat in South San Francisco
Authors
C. Alex Hartman, Joshua T. Ackerman, Mark P. Herzog, Yiwei Wang, Cheryl Strong

Genetics

In the current context of environmental changes, it is easy to see how extrinsic factors, such as shifts in sea surface temperature, food availability and accumulation of pollutants, can impact the health of marine mammals. However, intrinsic factors, including the genetic constitution of an individual, are also largely responsible for shaping health, particularly in terms of immune system effecti
Authors
Karina Acevedo-Whitehouse, Lizabeth Bowen

Longevity and population age structure of the arroyo southwestern toad (Anaxyrus californicus) with drought implications

The arroyo southwestern toad is a specialized and federally endangered amphibian endemic to the coastal plains and mountains of central and southern California and northwestern Baja California. It is largely unknown how long these toads live in natural systems, how their population demographics vary across occupied drainages, and how hydrology affects age structure. We used skeletochronology to es
Authors
Robert N. Fisher, Cheryl S. Brehme, Stacie A. Hathaway, Tim E. Hovey, Manna L. Warburton, Drew C. Stokes

Crowding affects health, growth, and behavior in headstart pens for Agassiz's desert tortoise

Worldwide, scientists have headstarted threatened and endangered reptiles to augment depleted populations. Not all efforts have been successful. For the threatened Agassiz's desert tortoise (Gopherus agassizii), one challenge to recovery is poor recruitment of juveniles into adult populations, and this is being addressed through headstart programs. We evaluated 8 cohorts of juvenile desert tortois
Authors
Jeremy S. Mack, Heather E. Schneider, Kristin H. Berry

Leaf to landscape responses of giant sequoia to hotter drought: An introduction and synthesis for the special section

Hotter droughts are becoming more common as climate change progresses, and they may already have caused instances of forest dieback on all forested continents. Learning from hotter droughts, including where on the landscape forests are more or less vulnerable to these events, is critical to help resource managers proactively prepare for the future. As part of our Leaf to Landscape Project, we meas
Authors
Koren R. Nydick, Nathan L. Stephenson, Anthony R. Ambrose, Gregory P. Asner, Wendy L. Baxter, Adrian J. Das, Todd E. Dawson, Roberta E. Martin, Tarin Paz-Kagan

Reproductive frequency and size-dependence of fecundity in the Giant Gartersnake (Thamnophis gigas)

How reproductive output changes with age or size is a key life-history trait that can affect which demographic rates most influence population growth. Although many studies have investigated the reproductive ecology of gartersnakes, we know little about reproduction in the threatened Giant Gartersnake, Thamnophis gigas. We used X-radiography to determine reproductive status and estimated fecundity
Authors
Jonathan P. Rose, Julia Ersan, Glenn D. Wylie, Michael L. Casazza, Brian J. Halstead